Lamp base



FIG. 1 is a front elevational view of a lamp base incorporating the inventive design, the lamp shade being shown in broken line for illustrative purposes only and forming no part of the claimed design;

FIG. 2 is a right-side view of the lamp base shown in FIG. 1;

FIG. 3 is a left-side view of the lamp base shown in FIG. 1; and,

FIG. 4 is a top view of the lamp base shown in FIG. 1.

The rear view of the inventive design is a mirror image of the design illustrated in FIG. 1, and the bottom of the lamp base is unadorned. 

The ornamental design for a lamp base, as shown and described. 